Concrete Masonry Units (CMU) are used in the construction of walls in buildings but have disadvantages that are costly to overcome. Block construction involves stacking CMU blocks in a grid pattern (typically 16 inch×8 inch grid) to form a wall. CMU is manufactured in a molding process that results in blocks that can vary in size plus or minus ⅛ inch within the height of a block.
Dry-stacking blocks with these inconsistencies in height would result in a wall that is out of plumb and level. The masonry industry has solved this problem by manufacturing CMU blocks to a size (typically 15⅝ inch×7⅝ inch) slightly smaller than their intended grid size. These masonry blocks are then stacked with a bed of mortar (typically ⅜ inch), to compensate for the smaller size, keeping the wall construction in line with the grid pattern established.
A skilled mason lays mortar on the previous course of CMU blocks thicker than required, stacks the next course of block on top of the mortar and taps on the top of the block until he compresses the mortar down and out so that the combination of the block and the mortar lines up with the grid pattern.
This process results in mortar thickness that varies to compensate for the inconsistent heights of plus or minus ⅛ inch in CMU masonry units and allows for the construction of plumb and level masonry walls.
Using STAY-IN-PLACE concrete forms constructed of concrete masonry shells with plastic web members is an alternative wall construction method that has been limited due to high labor cost associated with mortaring shells in place.
The present invention is a plastic connector that enables masonry shells of inconsistent dimensions with preformed channels to be snapped together while maintaining a gap of variable thickness between the shells such that the masonry shells and the gap fall within a predetermined grid pattern. The connectors perform the function of mortar joints in masonry construction while reducing the time, labor and skill required by eliminating mortaring joints as the masonry is set.
Mortar also has a set time that requires a waiting period before moving on to the next row of masonry shells. The present invention's plastic connectors have no set time. Masonry shells can be snapped together to form the opposing walls of a stay in place concrete form with no wait time, less labor and skill, while maintaining a predetermined grid pattern.
The connectors are also configured to accept plastic cross ties. Cross ties are required in concrete form work to restrain poured in place concrete between two opposing form walls.
The viscosity of the poured in place concrete can be controlled such that the uncured concrete will not leak out of the small variable gaps maintained by the plastic connector. Once the poured in place concrete has been cured, the gaps between the masonry shells can be left open, can be filled with caulk, can be filled with adhesive, or can be filled with mortar.
Prior art does not properly address using masonry shells of variable dimensions as the walls of concrete form work. Using shells of variable dimensions without compensating for this variation will result in walls that are out of plumb and level. Prior art teaches stacking and snapping together shells with consistent dimensions. Prior art teaches using mortar joints or adhesives or caulk to compensate for variations in shell sizes. The present invention teaches how to snap shells of inconsistent dimensions together with a plastic connector that compensates for the inconsistencies incrementally with each course of shells.
Conventional stay-in-place masonry forms come in the form of blocks that needed to be mortared into place, the same as normal masonry construction.
As can be seen, there is a need for an improved stay-in-place concrete form connector that allows masonry shell of variable dimensions to be dry stacked to form the walls of concrete form work.